Outcomes and the Value of Choice in Assignment Problems

This award funds research in economics that will develop and employ new methods to evaluate the results of existing matching systems. The project will also provide new insights into how to design such systems to meet societal goals. The research focuses on ideas that could improve the methods used in the U.S. and around the world to manage organ donations from deceased donors. The project will also evaluate the effects of recent changes to the system used in the U.S. to match donated organs to recipients. Donated organs are a scarce resource; in the U.S. alone approximately 22 people died each day in 2019 while waiting for a kidney transplant. This means that understanding the effects of current methods and the development of possible improvements could save lives. The new methods can also be applied to evaluate and possibly improve the effectiveness of many other systems that are used to match people to opportunities. For example, some public school systems use these ideas to place students in specific schools.

The project has several goals. The first is to develop methods that can be used to measure the performance of various assignment systems on these important outcomes. The proposed methods are based on combining data on outcomes and administrative data on the matching process to estimate the effects of various matches on the outcomes of interest, for example, the effects transplanting kidneys from different types of deceased donor to various patient types. The researchers will use quasi-experimental variation generated by the matching system to estimate these effects. The second goal is to apply these methods to study the life-year effects of different types of matches between different types of kidneys from deceased donors and patients with kidney failure. This part of the project improves on the current approach that uses an observational approach to estimate life-year benefits from kidney transplantation. The third goal is to understand how choices in a matching system relate to these outcomes of interest. Most matching mechanisms typically give patients a significant degree of choice. Patients and surgeons can accept or refuse an organ offer; students get to rank schools, and public housing applicants may apply to a subset of housing units. The goal is to understand the extent to which the people participating in these mechanisms make choices that are aligned with maximizing the outcomes such as survival effects in the case of kidney patients or test-score effects in the case of students. The final aim is to use these findings to evaluate existing matching systems and to design new systems. Moreover, the plan is to quantify the value of providing choice to agents. For example, it may be possible to use the assignment system to steer patients and their surgeons towards choosing the kidneys that are particularly well suited to them,but have little value for others. Improving the design along these dimensions can have a significant impact on patient health and survival.